There are multiple methods for manufacturing golf balls. In many methods, a core having one or more layers is formed from a variety of conventional methods. Various cover layers are then overlaid on top of the core layers. A mantle layer or other intermediate layer may also be incorporated.
The outermost layer may be considered to require the greatest degree of detail. The outermost layer typically includes a dimple pattern to create a desired set of aerodynamic properties. Often, the configuration of the dimple pattern must be precise in order to generate the specific desired aerodynamic properties.
Molding a precise the dimple pattern may be complicated by the use of one of the standard methods of molding the cover layers. In many methods, the cover is injection molded. When the cover is injection molded, the molding process may create a tab or burr that must be abraded from the surface of the ball, adding time and cost to the process.
In addition, the injection ports from which the material or polymer forming the cover layer is injected into the mold are often located on the land or fret areas of the ball between the dimples. The surface areas of these land areas are often quite small. Because the land areas are small, the injection ports that inject the cover material into the mold may be relatively small in size. The size of the ports also may limit the speed at which the cover material can be injected and therefore the speed at which the cover can be molded. While multiple ports can be used, the increase in the number of ports may require a corresponding increase in the number of burrs to be removed, further complicating the process and increasing the time and cost.
If, instead, the injection port were to be positioned adjacent a recessed dimple area, it would be possible to increase the size of the injection port to be approximately the same diameter as a dimple. However, the use of such a position for an injection port in a conventional molding apparatus and method may create a burr within the dimple, making it complicated or impossible to remove. When such a burr is not removed, it may create an undesirable aerodynamic effect.
Therefore, there exists a need in the art for an apparatus and method for injection molding a cover onto a ball where the injection port is sufficiently large to improve molding time while not creating additional aerodynamic consequences. Also, there exists a need in the art for an apparatus and method for injection molding a cover onto a ball which minimizes the need for a burr removal step.